Industrial Application of the Flushing Process to High Purification of Natural Raw Materials

为了高效分离陶瓷原料中的细杂质颗粒，笔者开发了冲洗工艺。在这个复杂的过程中，用煤油提取悬浮在原矿浆中的小于1mum的超细矿物颗粒。本文利用商用液-液连续萃取装置对天然无定形石墨和绢云母粘土进行了实验处理，以揭示该冲洗工艺在工业应用中的实用价值。为了进一步去除粘土杂质，选择了国内已富集的非晶石墨。产自台湾的绢云母粘土有时被用于化妆品中，以降低砷和铅的含量。冈山产的低品位绢云母中含有丰富的黄铁矿，黄铁矿的分离是其工业应用的必要条件。在冲洗操作之前，这些原料被按一定的微米级顺序分类。在柠檬酸、EDTA、二亚硝酸钠的存在下，将水泥浆的pH调至4.3，以提高提油所需物质的疏水性。确定了进给量、叶轮摆动次数、料浆密度、含料率等操作条件。日本Shimasaki制造公司生产的商用萃取器，由于其圆柱形叶轮，产生高剪切应力的细油滴，可用于疏水固体颗粒的收集，并将组成颗粒释放到单个颗粒中，因此在固体颗粒的萃取方面表现出优异的功能。通过添加非离子表面活性剂和碳酸钠，将萃取到油相中的石墨颗粒恢复到原来的水相分散体，并用离心机回收。2mum样品的灰分含量显著降低至1.8mass%，去除率为88.5%。此外，还对废油进行了硫酸洗涤再生。黄铁矿与绢云母粘土的分离效果良好。台湾绢云母中砷、铅的含量可降至化妆品标准值以下。对于冈山绢云母，原矿氧化后，其除铅效率降低。综上所述，实验结果表明，冲洗法对天然原料的技术提纯具有很大的优势。少

The flushing process was developed by the author for the purpose of highly efficient separation of fine impurity particles from ceramic raw materials. In this sophisticated process, ultrafine mineral particles of under 1mum size suspended in raw ore slurries are extracted with kerosene.In this report, a natural amorphous graphite and some sericite clays were treated experimentally using a commercial liquid-liquid continuous extraction apparatus to reveal the practical value of the flushing process in industrial application.The amorphous graphite which was already concentrated in China was selected for the further elimination of clayy impurities. The sericite clay occurring at Taiwan is sometimes required to lower the contents of As and Pb for the use in cosmetics. The low grade sericite occurring at Okayama contains abundant pyrite for which the separation of pyrite is necessary for its industrial application.These raw materials were classified at a certain size of micrometer order in … More prior to the flushing operation. The aqueous slurries were conditioned at pH 4.3 in the presence of citric acid, EDTA,sodium dithionite to enhance the hydrophobicity of desired substance for oil-extraction. Besides operational conditions were determined such as feed rate, numbers of oscillating motion of impeller, slurry density, hold-up fraction.The commercial extractor made by Shimasaki Manufacturing Co.showed excellent function for the oil-extraction of solid particles owing to its cylinder-shaped impeller by which high shearing stress fine oil droplets are created available for the collection of the hydrophobic solid particles, together with the release of the constituent particles to individual particles. The graphite particles extracted into the oil phase were returned to its original aqueous dispersions by the addition of nonionic surfactant and sodium carbonate and were recovered using centrifuge. The ash content of the 2mum sample was significantly lowered to 1.8mass% with the removed ratio of 88.5%. In addition, the waste oil was regenerated by washing with sulfuric acid.Separation of pyrite from the sericite clays was well performed. The content of As and Pb in Taiwan sericite could be lowered under the values of criterion for cosmetics. As to Okayama sericite, the efficiency of eliminating Pb was decreased when the raw ore had been oxidized.In conclusion, the experimental results suggest that the flushing process is very advantage for technical purification of natural raw materials. Less